Whistle and the like



Dec. 6, 1932'. A. l.. smoel-IAM WHISTLE AND THE LIKE Filed April 19.1932 q MQW MQW.. v AT-FERNE Patented Dec. 6, 1932 UNITED STATES PATENTGFFICE ARTHUR L. BRIDGHAM, F BOSTON, MASSACHUSETTS, ASSIGNOR T0 CHARLESH.' SHERBURNE, OF BOSTON, MASSACHUSETTS WHISTLE AND THE LIKE Application:filed April 19,

The invention relates to an improvement in whistles or like instrumentsin which sound is produced by the vibration of a contained column orbody of air and which vibration is generated by the application of agaseous fluid such as air or steam under what may be termed a soundingpressure.

The object of the invention is to provide means whereby a propersounding` pressure l0 upon the instrument may be obtained with a verysmall amount of air or steam relatively to the size of the instrument.

The invention can best be seen and understood by reference to thedrawing in which an embodiment thereof is shown applied to a whistle,and in which- Figure 1 is a front elevation of the whistle.

Fig. 2 is a cross section on the line 2-2 of Fig. 1, and

Fig. 3 shows partly in vertical cross section and partly in frontelevation a slightly modified form of the whistle applied to a valvecasing incidental to: an air brake system, in connection with which awhistle is commonly employed.

Referring to the drawing 1 represents the body of the whistle preterablytubular in form. The top end of said body is closed by a snugly ttingblock 2.

The opposite or lower end of the body 1 is leit open. Arranged oppositethis end and separated therefrom by a suitable air space 3 is a casing 4preferably tubular in form the same as the body 1. Contained within thiscasing is a block 5 which is joined to the block 2 by a connecting rod6. The two blocks and connecting rod are preferably integral. The lowerend portion 7 of the block 5 tits snugly within the casing while theupper end portion S thereof is of less diameter than the interior of thecasing leaving between it and the casing an annular space 9 whichcommunicates with the air space 3 and opposite end of the body 1 by wayof an annular port 10.

Communicating with the annular space 9 are intersecting cross passages11 extending through the block 5. Entrance is had to these passages byway of a passage 12 which extends through a bushing 13 screw-threaded tofit within the lower end portion 7 of the 1932. Serial No. 606,138.

blocl; 5. The bushing 13 is lborne by an inject-or block 14. Extendinglaterally through this block is a passage 15 connecting at its ends withthe outer air. Screw-threaded to t within the lower end portion of theblock 1e is a nozzle 16 with tip preferably contained within the passage15 below the entrance to the passage 12, the passage 17 thro-ugh thenozzle being in alignment with the passage 12. The nozzle is borne by ablock 18 of which it forms preferably an integral part. This block isinteriorly threaded to receive a connection (not shown) from anysuitable source of gaseous pressure.

The operation is as follows: Gaseous pressure induced to pass throughthe nozzle will induce a iow ot' atmospheric air entering by way of thepassage 15 to flow upwardly through the passage 12 into the passages 11and space 9 forming a compression chamber, and thence through the port10 across the air space 3 to impinge upon the end of the body 1 :torvibrating the air column within it.

In as far as the objective result is concerned the operation is the sameas in the case of an ordinary whistle or similar instrument such as anorgan pipe. T he means for accomplishing the objective result, is,however, diiierent in the sense that an iniiow of atmospheric air iscaused by the operation of the injector to constitute the essentialsounding pressure upon the body of the instrument. rlhis can perhaps bebetter appreciated by a consideration of the fact that if the amount oi'air or steam under pressure induced to 85 pass through the nozzle wasalone relied upon and all atmospheric air shut off, the soundingpressure on the body of the instrument would be entirely inadequate andno appreciable sound, if any, would result. Under the same conditions,however, with the same amount of air or steam passing through thenozzle, it then atmospheric air is admitted the sounding pressure uponthe instrument will be entirely adequate to provide sound of greatvolume and intensity.

lith a whistle of about the vsame general size as that shown in thedrawing and with an opening through the nozzlel of one sixteenth of aninch and under an entering pressimilar instrument with as little appliedpressure as possible. An instance of such is an air brake system havinga whistle and where there is great need of conserving the-air in thesystem and dissipating it as little as possible when the Whistle isblown. The result has been the use ofV a very wealr whistle for thereason that so little air could be used. IVith a less amount of air thanordinarily used for blowing the whistle in an air brake system one isenabled by admittingr an inflow of atmospheric air to obtain a soundingpressure suiicient to provide'a whistle .that can be heard at avery'long distance, and will lmeet all demands brought to bear upon it.

An example of the application of the present invention to the brakesystem is shown in Fig. 3. Here for purposes of expediency the whistleis made a little different frointhe rwhistle shown in Figs. l and 2although the pressure obtained from air within the brake system. Thesame casing is retained, and mounted upon this casing to formpractically an integral part thereof is the block 20 bearing theinjector nozzle 21. Screw-threaded `to iit upon the base of the nozzleis the injector block 22 and upon this block the body 28 of the whistleis mounted, the block fitting snugly within the lower end of said body.24 represents the entering passage for atmospheric air, the passageextending through the block 22 and that portion of the body of thewhistle within which the block fits. The outer or top end of the body ofthe whistle is open. s

Arranged above this end and'separated from .it by a suitable air space25 is a casing 26.

Contained within this casing is a block 27 Y which is joined to theinjector'block 22 by a connecting rod 28. The upper end portion of theblock 2T lits snugly within the casing. AThe lower portion thereof is ofless diameter than `the interior of the casing leaving be- Even tween itand the casing an annular space 29 which communicates with the air space25 and end of the body 23 by Way of an annular port 30. Communicatingwith the annular space 28 are intersecting cross passages 31, extendingthrough the block 27. Entrance is had to these passages by way of apassage 32 which extends through the rod 28 from the chamber of theinjector block 22 where atmospheric air is admitted.

The construction is substantially the same as-irst described, althoughthe arrangement is quite different especially in the fact that theentering air passing through the rod 28 is at a point some littledistance removed from the point where the soundingvpressure is ap- Aplied to the body ofthe instrument. The operation is the same as before.Pressure in duced to pass through the nozzle will cause a iiow of'atmospheric-air'- entering by way of the passage 24. to flow upwardly byway of the passage 32 into the passages 8l and space 29 and thencethrough the port 30 across the air space25 to impinge upon the end ofthe body 23 for vibrating the air column within it. Ilavingthus fullydescribed my invention, I claim and desire to secure by Letters Patentof the United States l In an instrument of the type specified, in

combination, spaced. casing portions, one of :1li

said casing portions having an air chamber, the other of said casingportions having an opening to the atmosphere and a compression chamber,said other casing portion having a passage connecting said opening and1@- compression chamber, and anozzle adapted to direct fluid underpressure into said passage and cause air to be drawn through saidopening int-o said passage, said other casing portion having means fordirecting iuid unjf-l der pressure from said compression'chamber towardsaid air chamber.

ARTHUR L. BRIDGHAM.l

